Methods for computer reading of ballistocardiograms (Bcg) and carotid pulses (CP) will be developed for an epidemiology study of coronary heart disease. These methods will then be employed to analyse 750 records of Bcg and CP collected by laboratories of the Coronary Drug Project (CDP). Inexpensive but adequate cassette tape recorders will be controlled by a specially designed device for precise formatting of analog magnetic tape. This "encoder" samples heartbeats for analysis and generates the desired patient identification number for recording. Recordings on analog magnetic tape are then converted to digital magnetic tape with appropriate format. These industry-compatible digital magnetic tapes are then analysed in batch process mode on IBM 370. Printer reports of individual patient studies of Bcg and CP are then provided CDP laboratories.